/*	archive.c - archive support			Author: Kees J. Bot *								13 Nov 1993 */#include "h.h"#ifdef unix#include <unistd.h>#include <fcntl.h>#define arraysize(a)	(sizeof(a) / sizeof((a)[0]))#define arraylimit(a)	((a) + arraysize(a))/* ASCII ar header. */#define ASCII_ARMAG	"!<arch>\n"#define ASCII_SARMAG	8#define ASCII_ARFMAG	"`\n"struct ascii_ar_hdr {	char	ar_name[16];	char	ar_date[12];	char	ar_uid[6];	char	ar_gid[6];	char	ar_mode[8];	char	ar_size[10];	char	ar_fmag[2];};/* ACK ar header. */#define	ACK_ARMAG	0177545#define ACK_AALMAG	0177454struct ack_ar_hdr {	char		ar_name[14];	unsigned long	ar_date;	unsigned char	ar_uid;	unsigned char	ar_gid;	unsigned short	ar_mode;	unsigned long	ar_size;};typedef struct archname {	struct archname	*next;		/* Next on the hash chain. */	char		name[16];	/* One archive entry. */	time_t		date;		/* The timestamp. */	/* (no need for other attibutes) */} archname_t;static size_t namelen;			/* Max name length, 14 or 16. */#define HASHSIZE	(64 << sizeof(int))static archname_t *nametab[HASHSIZE];_PROTOTYPE( static int hash, (char *name) );_PROTOTYPE( static int searchtab, (char *name, time_t *date, int scan) );_PROTOTYPE( static void deltab, (void) );_PROTOTYPE( static long ar_atol, (char *s, size_t n) );_PROTOTYPE( static int read_ascii_archive, (int afd) );_PROTOTYPE( static int read_ack_archive, (int afd) );static char *lpar, *rpar;	/* Leave these at '(' and ')'. */int is_archive_ref(name) char *name;/* True if name is of the form "archive(file)". */{  char *p = name;  while (*p != 0 && *p != '(' && *p != ')') p++;  lpar = p;  if (*p++ != '(') return 0;  while (*p != 0 && *p != '(' && *p != ')') p++;  rpar = p;  if (*p++ != ')') return 0;  return *p == 0;}static int hash(name) char *name;/* Compute a hash value out of a name. */{	unsigned h = 0;	unsigned char *p = (unsigned char *) name;	int n = namelen;	while (*p != 0) {		h = h * 0x1111 + *p++;		if (--n == 0) break;	}	return h % arraysize(nametab);}static int searchtab(name, date, scan) char *name; time_t *date; int scan;/* Enter a name to the table, or return the date of one already there. */{	archname_t **pnp, *np;	int cmp = 1;	pnp = &nametab[hash(name)];	while ((np = *pnp) != NULL			&& (cmp = strncmp(name, np->name, namelen)) > 0) {		pnp= &np->next;	}	if (cmp != 0) {		if (scan) {			errno = ENOENT;			return -1;		}		if ((np = (archname_t *) malloc(sizeof(*np))) == NULL)			fatal("No memory for archive name cache",(char *)0,0);		strncpy(np->name, name, namelen);		np->date = *date;		np->next = *pnp;		*pnp = np;	}	if (scan) *date = np->date;	return 0;}static void deltab()/* Delete the name cache, a different library is to be read. */{	archname_t **pnp, *np, *junk;	for (pnp = nametab; pnp < arraylimit(nametab); pnp++) {		for (np = *pnp; np != NULL; ) {			junk = np;			np = np->next;			free(junk);		}		*pnp = NULL;	}}static long ar_atol(s, n) char *s; size_t n;/* Transform a string into a number.  Ignore the space padding. */{  long l= 0;  while (n > 0) {	if (*s != ' ') l= l * 10 + (*s - '0');	s++;	n--;  }  return l;}static int read_ascii_archive(afd)int afd;/* Read a modern ASCII type archive. */{  struct ascii_ar_hdr hdr;  off_t pos= 8;  char *p;  time_t date;  namelen = 16;  for (;;) {	if (lseek(afd, pos, SEEK_SET) == -1) return -1;	switch (read(afd, &hdr, sizeof(hdr))) {	case sizeof(hdr):		break;	case -1:		return -1;	default:		return 0;	}	if (strncmp(hdr.ar_fmag, ASCII_ARFMAG, sizeof(hdr.ar_fmag)) != 0) {		errno= EINVAL;		return -1;	}	/* Strings are space padded! */	for (p= hdr.ar_name; p < hdr.ar_name + sizeof(hdr.ar_name); p++) {		if (*p == ' ') {			*p= 0;			break;		}	}	/* Add a file to the cache. */	date = ar_atol(hdr.ar_date, sizeof(hdr.ar_date));	searchtab(hdr.ar_name, &date, 0);	pos+= sizeof(hdr) + ar_atol(hdr.ar_size, sizeof(hdr.ar_size));	pos= (pos + 1) & (~ (off_t) 1);  }}static int read_ack_archive(afd)int afd;/* Read an ACK type archive. */{  unsigned char raw_hdr[14 + 4 + 1 + 1 + 2 + 4];  struct ack_ar_hdr hdr;  off_t pos= 2;  time_t date;  namelen = 14;  for (;;) {	if (lseek(afd, pos, SEEK_SET) == -1) return -1;	switch (read(afd, raw_hdr, sizeof(raw_hdr))) {	case sizeof(raw_hdr):		break;	case -1:		return -1;	default:		return 0;	}	/* Copy the useful fields from the raw bytes transforming PDP-11	 * style numbers to native format.	 */	memcpy(hdr.ar_name, raw_hdr + 0, 14);	hdr.ar_date=	  (long) raw_hdr[14 + 1] << 24			| (long) raw_hdr[14 + 0] << 16			| (long) raw_hdr[14 + 3] <<  8			| (long) raw_hdr[14 + 2] <<  0;	hdr.ar_size=	  (long) raw_hdr[22 + 1] << 24			| (long) raw_hdr[22 + 0] << 16			| (long) raw_hdr[22 + 3] <<  8			| (long) raw_hdr[22 + 2] <<  0;	/* Add a file to the cache. */	date = hdr.ar_date;	searchtab(hdr.ar_name, &date, 0);	pos= (pos + 26 + hdr.ar_size + 1) & (~ (off_t) 1);  }}int archive_stat(name, stp) char *name; struct stat *stp;/* Search an archive for a file and return that file's stat info. */{  int afd;  int r= -1;  char magic[8];  char *file;  static dev_t ardev;  static ino_t arino = 0;  if (!is_archive_ref(name)) { errno = EINVAL; return -1; }  *lpar= 0;  *rpar= 0;  file= lpar + 1;  if (stat(name, stp) < 0) goto bail_out;  if (stp->st_ino != arino || stp->st_dev != ardev) {	/* Either the first (and probably only) library, or a different	 * library.	 */	arino = stp->st_ino;	ardev = stp->st_dev;	deltab();	if ((afd= open(name, O_RDONLY)) < 0) goto bail_out;	switch (read(afd, magic, sizeof(magic))) {	case 8:		if (strncmp(magic, ASCII_ARMAG, 8) == 0) {			r= read_ascii_archive(afd);			break;		}		if ((magic[0] & 0xFF) == ((ACK_AALMAG >> 0) & 0xFF)			&& (magic[1] & 0xFF) == ((ACK_AALMAG >> 8) & 0xFF)		) {			r= read_ack_archive(afd);			break;		}		/*FALL THROUGH*/	default:		errno = EINVAL;		/*FALL THROUGH*/	case -1:		/* r= -1 */;	}	{ int e= errno; close(afd); errno= e; }  } else {	/* Library is cached. */	r = 0;  }  if (r == 0) {	/* Search the cache. */	r = searchtab(file, &stp->st_mtime, 1);  }bail_out:  /* Repair the name(file) thing. */  *lpar= '(';  *rpar= ')';  return r;}#endif